A number of electrical devices are present in a modern household. While some may be used directly by the user, others could be in use for years at a time. Many machines are subject to periodic breakdown, and the likelihood of breakdown increases as the age and hours of use increase. Many machines also require periodic maintenance such as, for example, lubrication or cleaning. The periodic maintenance may be essential for the operation of the device.
Machines that are most vulnerable to breakdown are often the most expensive. Such machines may contain large motors which must be run continuously. Nonstop operation may create conditions for the machine to become disabled. Foreign objects or lack of maintenance may result in catastrophic damage to the machine, which not only destroys the device but also could create a fire hazard.
Many devices operate continuously for the ease, comfort, and safety of loved ones. As an example, on hot summer days, it is common for pet owners to leave air conditioners on while they are away so their pets will stay cool. If the air conditioner were to fail, the pet may be harmed. As another example, a failed heating system may result in burst water pipes during the cold of winter. Therefore, failure of such electrical devices can potentially have many negative results.
In modern society, people are also interested in reducing energy consumption. However, people are prone to forgetfulness, making it very common for devices to be left on by accident. In addition, some may want a device to be on upon arrival to their home. Because of lack of a remote control, the device may be left on for an entire day. Thus, a large amount of energy may be wasted.